+ Post New Thread
Results 1 to 3 of 3
  1. #1
    Full Member level 6
    Points: 4,273, Level: 15
    Achievements:
    Created Blog entry Created Album pictures 7 years registered
    MahmoudHassan's Avatar
    Join Date
    Oct 2010
    Posts
    335
    Helped
    40 / 40
    Points
    4,273
    Level
    15
    Blog Entries
    8

    Output stages for opamp

    Hello
    Dear all ,
    I want to ask about a concept I want to understand, I read about output stages (Like the inverter one ) and I found that we can drive it in linear region to get maximum swing and that the input differential amplifier is designed to give the required gain.
    But if we drive the output stage into linear I think that the signal will be distorted at it's maximu voltage as part of signal running at good gain of the output stage and other parts will be run at lower gain at maximum of the signal
    so the output final signal will be distorted !! ?

    Click image for larger version. 

Name:	Selection_166.png 
Views:	14 
Size:	35.8 KB 
ID:	117502
    "I can't change the direction of the wind, but I can adjust my sails to always reach my destination."
    ~ by Jimmy Dean

    •   AltAdvertisment

        
       

  2. #2
    Full Member level 3
    Points: 1,611, Level: 9
    Debdut's Avatar
    Join Date
    Oct 2013
    Posts
    173
    Helped
    7 / 7
    Points
    1,611
    Level
    9

    Re: Output stages for opamp

    I think if the output stage is ensured to remain in triode region throughout its operating range, then the distortion will be less.
    However there will be still distortion due to variation of gm throughout the operating range.



    •   AltAdvertisment

        
       

  3. #3
    Super Moderator
    Points: 51,484, Level: 55
    Achievements:
    7 years registered
    erikl's Avatar
    Join Date
    Sep 2008
    Location
    Germany
    Posts
    8,064
    Helped
    2642 / 2642
    Points
    51,484
    Level
    55

    Re: Output stages for opamp

    Quote Originally Posted by Debdut View Post
    I think if the output stage is ensured to remain in triode region throughout its operating range, then the distortion will be less.
    I'm sure you thought of saturation region ?

    Quote Originally Posted by MahmoudHassan View Post
    ... if we drive the output stage into linear I think that the signal will be distorted at it's maximu voltage as part of signal running at good gain of the output stage and other parts will be run at lower gain at maximum of the signal
    so the output final signal will be distorted !! ?
    Each amp has its own ICMR and its "undistorted" output range, their limits given by the acceptable distortion limits of the application. In the linear range between these limits, distortion can be reduced by high gain and strong (linear) feedback.


    1 members found this post helpful.

--[[ ]]--